DE 40 34 528 C2 describes a connection arrangement in double sickle bars of front mowers between a sickle drive and a linearly reciprocating sickle. The introduction of the reciprocating movement is achieved, via a pivoting drive lever, and an activated driving trunnion. The driving lever is connected via a spherical bearing to the sickle. The spherical bearing arrangement is necessary, as the driving trunnion is moved by its connection to the drive lever following its pivot movement on a circular path. As the sickle is only linearly guided reciprocatingly movable, the arrangement has to constantly allow for, during operation, a pivot movement of the driving trunnion in relation to the connection element connected to the sickle as well as an axial displacement of the driving trunnion. The connection element that serves to connect to the sickle has a formed ring-like portion and therein a circular cylindrical bore. In this bore, an intermediate ring, closed in a circumferential direction, is accommodated and fixed with its circular cylindrical outer face adapted to the bore. The intermediate ring has a spherical inner face. In this spherical inner face, a bearing ring, which is closed in a circumferential direction, is pivotably movably accommodated with a spherical outer face. The bearing ring has a circular cylindrical through bore. The driving trunnion rests in this through bore displaceably along the axis of the through bore, to be able to compensate for the positional change relative to the displacement axis of the sickle, resulting from the movement of the driving trunnion with the driving lever on a circular path. The whole connection arrangement is inclined, in relation to a longitudinal axis of the driving trunnion, in a direction towards the sickle. To ensure a lubrication chamber for the spherical faces, a lid, which seals the bore downwards, is inserted into the circular cylindrical bore of the connection element in a direction towards the sickle. On the opposite side of the bore, a boot is provided, which seals the bore relative to the driving trunnion.
DE 10 2006 010 825 B4 illustrates a known connection arrangement. It has a connection element on the sickle that is at least partially formed as an open ring and has a through bore extending along a longitudinal axis. Furthermore, an intermediate ring is provided that rests in the through bore of the connection element. It has a spherical inner face and at least one slot on its circumference. In the intermediate element, a rolling member bearing is accommodated with a spherical outer face adapted to the spherical inner face. A disadvantage is that specially sealed rolling member bearings have to be used to ensure a lasting lubrication of the rolling member bearing and to protect this against dirt.